Heat exchanger valve



K. GROSJEAN INVENTOR Kurt Grosjeon W,.W9mfw'ze ATTORNEYS United StatesPatent Ofitice 7 3,019,985 Patented Feb. 6, 1962 3,019,985 HEATEXCHANGER VALVE Kurt Grosjean, Zug, Switzerland, assignor to Landis &

Gyr, A.G., Zug,-Switzerland, a corporation of Switzerland Filed Dec. 29,1959, Ser. No. 862,581 (llaims priority, application Switzerland Jan.14, 1959 3 Claims. (Cl. 236-1) This invention relates to a thermostatic,heat-exchanger regulator valve for automatic changeover to heating orcooling regulation and more particularly to such a valve having improvedcontrol valve means. I

A known thermostatic, heat-exchange regulator valve for automaticchangeover to heating or cooling regulation such as disclosed in PatentNo. 2,936,121 issued to the assignee of the instant application,comprises a diaphragm pressure member which is subject to adesired-value setting and detects the room temperature by means of aliquid temperature sensor and also includes a control valve having twothrottle members working in opposition, one of which is effective duringheating operation and the otherduring cooling operation. This controlvalve is subject to theinfluence of the diaphragm pressure member andcontrols a hydraulic servornotor for opening and closing the main valve.The changeover of the throttle members of the control valve, on changingthe installation from heating to cooling or vice versa, is efi'ectedautomatically by means of a bimetal disc which is exposed to thetemperature of the heating or cooling medium. In the known arrangementthe throttle members of the control valve are constructed in the form ofpoppet valves arranged one behind the other and the bimetal disc is asnap disc. Both the poppet-valvertype throttle members, and the bimetalsnap spring, have proved unsuitable in that these means are difficult toadjust. j The object of the present invention is an improvement to saidcontrol valve. A specific object of the invention is to provide a valvecapable of being readily'and accurately adjusted.

Another object of the invention is to provide a valve capable of beingadjusted for difierent conditions in which said adjustments may beindependently made.

These and other objects and advantages of'the inventionwill be set forthin part hereinafter and in part will be obvious herefrom, or may belearned by practice with the invention, the same being realized andattained by means of the instrumentalities and combinations pointed outin the appended claims. 1

The invention, briefly and generally, comprises a thermostatic heatexchanger regulator valve for automatic changeover to heating or coolingregulation and includes a control valve for a hydraulic servomotor whichconsists of a two-armed rocker which carries two bimetal strips bendingin opposite directions and additionally includes two throttle membersconstructed in the form of ball valves, each of said ball valves and thefree end of each bimetal strip lying respectively under each end of therocker. Dependingon the temperature of the heating or cooling medium,one or the other bimetal strip acts on the associated ball valve whilethe other bimetal strip is bent out of its range of action towards therocker; the control is eifected as a result of the fact that thediaphragm pressure member presses on one rocker arm and a compressionspring acting as a counteracting force presses on the other rocker arm.The particular ball valve which is inoperative is held closed by a leafspring.

In one embodiment of the invention automatic changeover of the controlvalve to heating or cooling is accomplished within a very narrowtemperature range of the drop of the medium and hence a precisedimensioning of the required servo force is rendered possible. I

The invention consists in the novel parts, constructions, arrangements,combinations and improvements herein shown and described. 7 t 7 Oneembodiment of the subject of the invention is illus trateddiagrammatically by way of example in the draw- The housing of theregulator valve consists of four parts, namely a lower part-1 with thebase 23, an upper part 6 and a cover 1 6. The lower part 1 of thehousing has an inlet connection2, an outlet connection 3 and acylindrical center portion 4 in the axis of which is mount ed the mainvalve 5 for opening and closing. The upper part 6 of the housing ismounted on the cylindrical center portion 4. The parts 4 and 6 of thehousing together form a hollow chamber which is divided by a settingdiaphragm 7 into a low-pressure chamber 8 and a highpressure chamber 9.The, pressure drop for the two chambers 8 and 9 is produced as a resultof the fact that in the lower part 1 of the housing, the passage betweenthe inlet and outlet connections :2 and 3 respectively is constructed inthe form of a venturi tube 10; the highpressure chamber 9 is connectedby athrottle 12 and a high-pressure passage 11 to the inlet 2; and thelowpressure chamber 8 is connected by a low-pressure passage 13 to theconstricted part of the outlet '3 behind the main valve 5. In ordertocontrol the pressure drop, the high-pressure chamber 9.is connectedtothe low-pressure chamber 8 through a control valve mounted on a plate14, with two ball valves 21, 22 serving as throttle members. Theconnection is completed-through a passage 15.-

Mounted on the upper part of the housing is the cover 16 which comprisesa diaphragm pressure member 17 which is connected through a capillarytube, 18 top liquid temperature sensor which is not illustrated. Theposition of-the diaphragm pressure member 17 'can be adjusted inrelationto the control valve by means of adesired-value setscrew 19 in order toset the temperature to be maintained. The diaphragm pressure member 17acts .by means of a push rod .20 on the control valve device.

In order to produce an opposing force for the setting diaphragm 7, thereis provided in a hollow space between the 'lower part 1 of the housingand the base 23, a restoring diaphragm 24 which divides the hollow spaceinto a lower high-pressure chamber'26'connected through a passage 25 tothe inlet 2, and-an upper low-pressure chamber 28 connected through apassage 27 to the constricted part of the outlet 3. The pressure of theheating orcooling medium on the restoring diaphragm 24 is not controlledand depends on the pump pressure. If the control force on the settingdiaphragm 7 is greater than the counteracting force on the restoringdiaphragm 24, the main valve 5 is closed; if the control force is less,it is open. v V V The control valve comprises a twoarmed r'ocker 30which is pivotal-lymounted about a pin 29 or, preferably, on pivots orknife edges, and which is arranged in such a manner that the ball valve21 is below the left-hand end and the ball valve 22 below the right-handend of the rocker 30. On the under side of the rocker, that is to say onthe side facing the plate 14, two bimetal strips 31, 32 are secured insuch a manner that one free end of each is opposite one end of therocker 3t} and one ball valve. At their free ends, the two bimetalstrips 31, 32 each carry a screw stud 33 or 34, which can be screwedinto a thread provided in the bimetal and which presses downwards on thecorresponding ball valve and can thus release the valve passageconcerned. Each of the screw studs 33, 34 projects upwards through anaperture in the associated arm of the rocker and each is provided, atits upper end, with a screw head 35 or 36, which can rest on the rocker30. The two bimetal strips 31, 32 are arranged in such a manner thatthey bend in opposite directions, that is to say, during heating, thebimetal strip 31 bends downwards towards the valve 21 and the bimetalstrip 32 bends upwards towards the rocker 36; the bending takes place inthe reverse direction during cooling. The deflection of a bimetal stripin the direction of the associated ball valve, that is to say of thebimetal strip 31 during heating and of the bimetal strip 32 duringcooling, is limited in each case by the corresponding screw head 35 or36. In this end position, the bimetal strips run substantially parallelto the rocker arms and the screw heads 35 and 36 bear with pressureagainst the ends of the rocker arms. Leaf springs 37, 38 on the underside of the plate 14 each urge their associated valve ball 21 or 22 intothe corresponding valve seating while stops 39 and 40 respectively eachprevents the associated valve ball from being pushed too far out andfalling out. The push rod 20 of the diaphragm pressure member 17 presseson the right-hand rocker arm, the bimetal strip 32 of which is inoperation during cooling. A compression spring 41 which serves as acounteracting force, presses on the lefthand rocker arm, the bimetalstrip 31 of which is in operation during heating.

The drawing shows the regulating valve during heating. The two hal-lvalves 21, 22 of the control valve are at first closed. The pressure ofthe medium therefore rises in the chamber 9 and the setting diaphragm 7closes the main valve 5. As a result of the throttling of the heatingmedium, the temperature to be controlled drops and the push rod 20 ofthe diaphragm pressure member 17 is lifted. As a result, the rocker 30is inclined towards the left and the screw stud 33 urges the ball valve21 downwards so that theassociated valve passage is opened. The pressurein the chamber 9 therefore decreases and the main valve opens under thecounter pressure of the restoring diaphragm 24. If the temperature to becontrolled rises, the diaphragm pressure member 17 expands and the pushrod 20 urges the right-hand arm of the rocker downwards as a result ofwhich the lefthand arm thereof is raised accordingly, so that the ball21 again closes its valve passage.

On changing over from heating to cooling, that is to say within atemperature range of the heating or cooling medium lying, for examplebetween 28 to 29 C. and 21 to 22 C., the bimetal strip 31 bends towardsthe rocker 30 and the bimetal strip 32 stretches. As a result, theright-hand end of the rocker 30 is lowered and the screw stud 34 urgesthe valve ball 22 downwards so that the associated valve passage isopened. As a result, the pressure in the chamber 9 decreases and themain valve 5 opens so that the cooling medium can now flow through. Ifthetemperature to be controlled drops to the set desired value, the pushrod 20 is raised and so, too, is the right-hand end of the rocker 30, asa result of which the valve ball 22 closes the associated valve passageand so The control valve according to the invention has the advantagethat the distances between the screw studs 33, 34 and the associatedvalve balls 21, 22 and the distance between the screw heads 35, 36 andthe rocker 30 can be easily and accurately adjusted. The simple bimetalstrips provided for the changeover to heating or cooling comprise adeflection of their free ends which permits control in a temperaturerange of about 6 to 8 C.

he invention in its broader aspect is not limited to the specificmechanisms shown and described but departures may be made therefromwithin the scope of the accompanying claims without departing from theprinciples of the invention and without sacrificing its chiefadvantages.

What is claimed is:

1. In a thermostatic, heat exchanger regulator valve for controlling theflow of a liquid medium during heating and cooling functions comprisinga diaphragm pressure member and hydraulic servo means including acontrol valve for controlling the flow of said liquid medium, saidcontrol valve being controlled according to the pressure exerted by saiddiaphragm pressure member, means for improving said control valvecomprising a two-armed rocker, Said rocker being urged in one directionby said diaphragm pressure member and in the opposite direction by acompression spring, two bimetal strips carried by said rocker, saidstrips having free ends lying respectively under said arms of saidrocker and being adapted to bend in opposite directions relative totheir respective arms in response to a particular temperature conditionof said liquid medium, a pair of throttle members each comprising a ballvalve, said throttle members being disposed respectively below said armsof said rocker and said free ends of said strips, leaf spring meansadjacent said ball valves for urging said Valves into the closedposition, each of said throttle members being located to control theactuation of said control valve and each being controlled according tothe position of the associated strip whereby a change in temperatureduring heating functions causes one of said strips to actuate theassociated throttle member to thereby actuate said control valve whilethe other said strip moves away from its associated throttle member,whereas a change in temperature during cooling functions causes saidother strip to actuate its associated throttle member to thereby actuatesaid control valve, while the first one of said strips moves away fromits associated throttle member.

2. A regulating valve as claimed in claim 1, wherein each of the arms ofsaid rocker includes means defining an aperture in the end thereof, eachof said bimetal strips carries, at its free end, a screw stud which isperpendicular thereto and which can be screwed into the bimetal strip,one end of the screw stud cooperating with the associated ball valve,the other end projecting through the aperture provided at the end of oneof said rocker arms, said projecting end carrying a screw head which isadapted to limit the deflection ofthe bimetal strip in relation to therocker by bearing against the latter.

3. A regulating valve as claimed in claim 1, characterized in that saidrocker is mounted on pivot bearings.

References Cited in the file of this patent UNITED STATES PATENTS1,270,438 Roesch June 25, 1918 2,309,848 King Feb. 2, 1943 2,805,025Dillrnan Sept. 3, 1957

